The relevance of inertia-capillary dynamics on superhydrophobic heat exchange, microscopic phase change, and bloodstains

For most surfaces, an impacting water drop will stick upon contact; however, for a superhydrophobic surface, an impacting water drop can spread out and recoil to such an extreme that it can completely bounce off of the surface. The duration for which a drop is in contact with the surface depends on a balance between inertial and capillary effects, leading to a contact time often on the order of milliseconds. Previous studies have focused on the dynamics of the drop interface during this short time; however, it is unclear in what ways the inertia-capillary dynamics interact with transport phenomena across the interface that might occur on similar timescales. Here we combine modeling and experiments to investigate the relevance of the inertia-capillary dynamics on three interfacial transport processes: superhydrophobic heat exchange, microscopic phase change, and on the size and shape of dried bloodstains. Our first study focuses on heat exchange between a bouncing drop and a superhydrophobic substrate. By measuring the thermal interaction between a superhydrophobic substrate and a heated or cooled drop, we demonstrate that the contact time is short enough that only a small fraction of potential heat is transferred, and, counter-intuitively, smaller drops transfer a larger fraction of their potential heat than larger drops despite contacting the surface for less time. Our results indicate that birds with superhydrophobic feathers will be warmer in cold rain than those with feathers on which drops stick, and we envision that a better understanding of these mechanisms can inspire the design of novel superhydrophobic materials to control heat exchange. Our next study focuses on certain superhydrophobic surfaces that a water drop will stick on them rather than bounce if it is sufficiently hot. We model two potential mechanisms in which a superhydrophobic surface could trap a sufficiently hot drop within milliseconds: a microtexture melting mechanism and an evaporation–condensation mechanism. Ultimately, we aim to address how one might design a smart superhydrophobic surface in which the surface can sense a property of the drop, here its temperature, and, if above a critical threshold, passively adjust its functionality so that it will capture the drop and act as a rapid thermal fuse. Our last study focuses on how microscopic coatings can modify bloodstain shapes and sizes with the goal of challenging some tacit assumptions in forensics. We demonstrate that the inertia-capillary dynamics sets the size of bloodstains on different coatings, including on unintentional coatings, such as the sebaceous residue from a latent fingerprint. Since the stain size and shape can be critical in conducting a bloodstain pattern analysis, our results highlight the need for forensic analysts to exercise caution when evaluating bloodstains on surfaces that might contain coatings or residues

A Model of Transient Heat Transfer in a Packed Bed of Alumina Particles

The present study seeks to develop a robust system-scale heat transfer model for a sensible heat storage system. A novel mechanism to simulate axial dispersion and heat loss from the boundary of the sensible heat system to the environment is introduced. The most challenging topics to develop a robust heat transfer model are related to heat loss term, selecting the more reliable method to calculate heat transfer coefficient between fluid and solid, and investigating the effect of neglecting temperature dependency of materials properties. As the storage heat system has a vertical storage vessel, the dominant heat transfer mechanism from the boundaries of the vessel is free heat convection. In other words, there is no heat loss from the walls except the heat loss happening between walls of the vessel and the ambient by free convection. This model shows heat transfer coefficient is a function of time because of the changing hot zone length. The hot zone length is increased over time and this causes increase of Grashof number and finally Nusselt number or heat convection coefficient to the ambient. Material property changes are another matter considered in the model. The temperature of the system is varied considerably (absolute temperature is designed to change by roughly a factor of two) over a storage cycle and this affects the material properties of the solid beads and fluid flow. Results show that considering this point has a very significant effect when temperatures are (as expected in application) far above the ambient

Biomedical Applications of Zeolitic Nanoparticles, with an Emphasis on Medical Interventions

The advent of porous materials, in particular zeolitic nanoparticles, has opened up unprecedented putative research avenues in nanomedicine. Zeolites with intracrystal mesopores are low framework density aluminosilicates possessing a regular porous structure along with intricate channels. Their unique physiochemical as well as physiological parameters necessitate a comprehensive overview on their classifications, fabrication platforms, cellular/macromolecular interactions, and eventually their prospective biomedical applications through illustrating the challenges and opportunities in different integrative medical and pharmaceutical fields. More particularly, an update on recent advances in zeolite-accommodated drug delivery and the prevalent challenges regarding these molecular sieves is to be presented. In conclusion, strategies to accelerate the translation of these porous materials from bench to bedside along with common overlooked physiological and pharmacological factors of zeolite nanoparticles are discussed and debated. Furthermore, for zeolite nanoparticles, it is a matter of crucial importance, in terms of biosafety and nanotoxicology, to appreciate the zeolite-bio interface once the zeolite nanoparticles are exposed to the bio-macromolecules in biological media. We specifically shed light on interactions of zeolite nanoparticles with fibrinogen and amyloid beta which had been comprehensively investigated in our recent reports. Given the significance of zeolite nanoparticles’ interactions with serum or interstitial proteins conferring them new biological identity, the preliminary approaches for deeper understanding of administration, distribution, metabolism and excretion of zeolite nanoparticles are elucidated

Estimates, trends, and drivers of the global burden of type 2 diabetes attributable to PM2.5 air pollution, 1990-2019 : an analysis of data from the Global Burden of Disease Study 2019

Background Experimental and epidemiological studies indicate an association between exposure to particulate matter (PM) air pollution and increased risk of type 2 diabetes. In view of the high and increasing prevalence of diabetes, we aimed to quantify the burden of type 2 diabetes attributable to PM2.5 originating from ambient and household air pollution.Methods We systematically compiled all relevant cohort and case-control studies assessing the effect of exposure to household and ambient fine particulate matter (PM2.5) air pollution on type 2 diabetes incidence and mortality. We derived an exposure-response curve from the extracted relative risk estimates using the MR-BRT (meta-regression-Bayesian, regularised, trimmed) tool. The estimated curve was linked to ambient and household PM2.5 exposures from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, and estimates of the attributable burden (population attributable fractions and rates per 100 000 population of deaths and disability-adjusted life-years) for 204 countries from 1990 to 2019 were calculated. We also assessed the role of changes in exposure, population size, age, and type 2 diabetes incidence in the observed trend in PM2.5-attributable type 2 diabetes burden. All estimates are presented with 95% uncertainty intervals.Findings In 2019, approximately a fifth of the global burden of type 2 diabetes was attributable to PM2.5 exposure, with an estimated 3.78 (95% uncertainty interval 2.68-4.83) deaths per 100 000 population and 167 (117-223) disability-adjusted life-years (DALYs) per 100 000 population. Approximately 13.4% (9.49-17.5) of deaths and 13.6% (9.73-17.9) of DALYs due to type 2 diabetes were contributed by ambient PM2.5, and 6.50% (4.22-9.53) of deaths and 5.92% (3.81-8.64) of DALYs by household air pollution. High burdens, in terms of numbers as well as rates, were estimated in Asia, sub-Saharan Africa, and South America. Since 1990, the attributable burden has increased by 50%, driven largely by population growth and ageing. Globally, the impact of reductions in household air pollution was largely offset by increased ambient PM2.5.Interpretation Air pollution is a major risk factor for diabetes. We estimated that about a fifth of the global burden of type 2 diabetes is attributable PM2.5 pollution. Air pollution mitigation therefore might have an essential role in reducing the global disease burden resulting from type 2 diabetes. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Peer reviewe

Estimates, trends, and drivers of the global burden of type 2 diabetes attributable to PM2.5 air pollution, 1990-2019 : An analysis of data from the Global Burden of Disease Study 2019

Background Experimental and epidemiological studies indicate an association between exposure to particulate matter (PM) air pollution and increased risk of type 2 diabetes. In view of the high and increasing prevalence of diabetes, we aimed to quantify the burden of type 2 diabetes attributable to PM2·5 originating from ambient and household air pollution. Methods We systematically compiled all relevant cohort and case-control studies assessing the effect of exposure to household and ambient fine particulate matter (PM2·5) air pollution on type 2 diabetes incidence and mortality. We derived an exposure–response curve from the extracted relative risk estimates using the MR-BRT (meta-regression—Bayesian, regularised, trimmed) tool. The estimated curve was linked to ambient and household PM2·5 exposures from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, and estimates of the attributable burden (population attributable fractions and rates per 100 000 population of deaths and disability-adjusted life-years) for 204 countries from 1990 to 2019 were calculated. We also assessed the role of changes in exposure, population size, age, and type 2 diabetes incidence in the observed trend in PM2·5-attributable type 2 diabetes burden. All estimates are presented with 95% uncertainty intervals. Findings In 2019, approximately a fifth of the global burden of type 2 diabetes was attributable to PM2·5 exposure, with an estimated 3·78 (95% uncertainty interval 2·68–4·83) deaths per 100 000 population and 167 (117–223) disability-adjusted life-years (DALYs) per 100 000 population. Approximately 13·4% (9·49–17·5) of deaths and 13·6% (9·73–17·9) of DALYs due to type 2 diabetes were contributed by ambient PM2·5, and 6·50% (4·22–9·53) of deaths and 5·92% (3·81–8·64) of DALYs by household air pollution. High burdens, in terms of numbers as well as rates, were estimated in Asia, sub-Saharan Africa, and South America. Since 1990, the attributable burden has increased by 50%, driven largely by population growth and ageing. Globally, the impact of reductions in household air pollution was largely offset by increased ambient PM2·5. Interpretation Air pollution is a major risk factor for diabetes. We estimated that about a fifth of the global burden of type 2 diabetes is attributable PM2·5 pollution. Air pollution mitigation therefore might have an essential role in reducing the global disease burden resulting from type 2 diabetes

Trapping a Hot Drop on a Superhydrophobic Surface with Rapid Condensation or Microtexture Melting

A water drop can bounce upon impacting a superhydrophobic surface. However, on certain superhydrophobic surfaces, a water drop will stick rather than bounce if it is sufficiently hot. Here, we aim to better understand the mechanisms that can lead to this bouncing-sticking transition. Specifically, we model two potential mechanisms in which a superhydrophobic surface could trap a sufficiently hot drop within milliseconds: melting of microtextured wax and condensation of the vapor within the superhydrophobic texture. We then test these mechanisms through systematic drop impact experiments in which we independently vary the substrate and drop temperatures on a waxy superhydrophobic Nasturtium leaf. We find that, whenever the surface or the drop is above a microtexture-melting temperature, the drop sticks. Below this temperature, a critical temperature threshold for bouncing can be predicted and controlled by considering the relative timescales between condensation growth and drop residence time. We envision that these results can provide insight into the design of a new class of superhydrophobic surfaces to act as a rapid thermal fuse to prevent drops that exceed a critical temperature from bouncing onto a thermally sensitive target

The role of corporate governance in investment efficiency and financial information disclosure risk in companies listed on the Tehran stock exchange

This study's primary purpose is to investigate corporate governance's role in investment efficiency and financial information disclosure risk in companies listed on the Tehran Stock Exchange. A multivariate linear regression model based on the panel data model was used to test the research hypotheses. The results of the survey of 140 companies listed on the Tehran Stock Exchange from 2015 to 2021 indicate that investment efficiency has increased by increasing the quality of corporate governance. In addition, research findings show that improving the quality of corporate governance reduces the risk of financial information disclosure. The life cycle and firm size were used to evaluate the robustness of the results obtained in this study. It was observed that improving corporate governance in companies in the stages of growth and maturity increases investment efficiency and reduces the financial information disclosure risk. In contrast, in companies that are in the decline stage, it reduces investment efficiency and increases the risk of financial information disclosure. In terms of firm size, it was also observed that, in small firms, as corporate governance increases, investment efficiency decreases, and the risk of financial information disclosure increases. However, investment efficiency and financial information disclosure reduce risk by improving large companies' corporate governance

Trapping a Hot Drop on a Superhydrophobic Surface with Rapid Condensation or Microtexture Melting

A water drop can bounce upon impacting a superhydrophobic surface. However, on certain superhydrophobic surfaces, a water drop will stick rather than bounce if it is sufficiently hot. Here, we aim to better understand the mechanisms that can lead to this bouncing-sticking transition. Specifically, we model two potential mechanisms in which a superhydrophobic surface could trap a sufficiently hot drop within milliseconds: melting of microtextured wax and condensation of the vapor within the superhydrophobic texture. We then test these mechanisms through systematic drop impact experiments in which we independently vary the substrate and drop temperatures on a waxy superhydrophobic Nasturtium leaf. We find that, whenever the surface or the drop is above a microtexture-melting temperature, the drop sticks. Below this temperature, a critical temperature threshold for bouncing can be predicted and controlled by considering the relative timescales between condensation growth and drop residence time. We envision that these results can provide insight into the design of a new class of superhydrophobic surfaces to act as a rapid thermal fuse to prevent drops that exceed a critical temperature from bouncing onto a thermally sensitive target

Self-Assessment the Competence of the Anesthesia Personnel in Kashan, Iran, and Its Related Factors

Background & Aims One of the goals of providing training to the anesthesia care team is to train staff with theoretical and functional abilities to deal with clinical challenges. However, there is a gap between the existing and desired performance levels of personnel in anesthesia procedures. This study aims to assess the competence of anesthesia personnel in Kashan, Iran, and find its related factors. Materials & Methods This descriptive-analytical study was conducted on 95 anesthesia personnel of hospitals in Kashan, Iran, in 2023, who were selected using a census method. The data collection tools were a demographic form and the Anesthesia Nursing Competence Scale. Data were analyzed in SPSS v.22 software using descriptive statistics (frequency, mean, standard deviation), Mann-Whitney U test, Kruskal-Wallis test, Spearman’s correlation test, Point-Biserial correlation test, and regression analysis. Results The mean age of the participants was 34.57±10.1 years. The overall competence level of anesthesia personnel was at a high level (84.84±53.11). Their competence had a significant relationship with their sex and marital status (P<0.05). Conclusion The competencee of anesthesia personnel in Kashan is at a high level in all fields, except for the patient’s risk care. It is recommended to empower personnel in this area to prevent adverse events and improve the quality of medical services

Marangoni spreading and contracting three-component droplets on completely wetting surfaces

SignificanceThe shape and dynamics of small sessile droplets are dictated by capillary forces. For liquid mixtures, evaporation adds spatio-temporal modulation to these forces that can either enhance or inhibit droplet spreading, depending on the direction of the resulting Marangoni flow. This work experimentally and numerically demonstrates the coexistence of two antagonistic Marangoni flows in a ternary mixture. Played against each other, they can choreograph a boomerang-like wetting motion: Droplets initially rapidly spread, then contract into a compact cap shape. While such a behavior has been impossible in wetting scenarios of simple liquids, it enables spread-retract-remove surface processing with the addition of a single small liquid volume, demonstrated here in a surface-cleaning experiment.ISSN:0027-8424ISSN:1091-649